1. Field of the Invention
The present invention relates to heat exchangers such as laminated evaporators for used in automobile air-conditioners, and more particularly to a laminated heat exchanger composed a multiplicity of laminated heat exchanger elements having pairs of tanks at one side thereof and communicated together by U-shaped flow passages or channels.
2. Description of the Prior Art
One known laminated evaporator is disclosed in Japanese Patent Laid-open Publication No. 61-184394 in which an inlet pipe and an outlet pipe are connected to the front of an evaporator body as viewed from the direction of flow of air to be cooled.
The inlet and outlet pipes connected to the front of the evaporator body is disposed in the air flow passage and hence forms an obstacle or resistance to the flow of air which will lower the cooling power of the evaporator. Furthermore, since the inlet and outlet pipes are provided with pressure reducing valves and the like, the location of these pipes in the air flow passage results in an obstructed flow of air to be cooled through the air flow passage.
Japanese Utility Model Laid-open Publication No. 60-154774 discloses an arrangement which comprises an inlet pipe and an outlet pipe disposed on opposite sides of an evaporator body. With the inlet and outlet pipes disposed on the different sides, the evaporator requires a complicated arrangement for connection with a related devices and also needs a wasteful room for installation thereof.
It is therefore desired that inlet and outlet pipes are disposed on one side of an evaporator body in side-by-side.
In an evaporator having a so-called "two-path" flow pattern wherein a refrigerant flows from one of a pair of laterally spaced tanks to the opposite tank through a U-shaped flow passage or channel, the inlet and outlet pipes can be disposed on one side of the evaporator body in side by side. In a large-sized evaporator, the two-path flow pattern is however unable to provide an adequate heat exchanging efficiency. It is therefore desirable for the evaporator to have a flow pattern having at least four flow paths. In order to form a refrigerant flow passage having at least four paths, the inlet and outlet pipes must be disposed on opposite sides of the evaporator body. Thus, the side-by-side arrangement of the inlet and outlet pipes becomes impossible again.